accipitridae aegithalidae anatidae anseriformes apodiformes archaeopteryx auk avian incubation aviculture barbet bird bird anatomy bird collections bird conservation bird evolution bird feeding bird flight bird hybrid bird intelligence bird migration bird nest bird of prey bird ringing bird vision bird vocalization birdwatching brood parasite buttonquail callaeidae cape horn caprimulgiformes cassowary casuariidae chachalaca charadriidae charadriiformes charles sibley ciconiiformes cisticolidae coccyzidae cockatoo columbidae columbiformes coraciiformes corvida corvidae cracidae crotophagidae cuckoo cuculiformes dna-dna hybridization dinosaur diver duck enantiornithes eurostopodidae falconidae falconiformes feather flamingo formicariidae frigatebird galbuliformes galliformes glareolidae grebe gruiformes gull heliornithidae heron hesperornithes hoopoe hornbill hummingbird jacamar jon edward ahlquist kiwi late quaternary prehistoric birds limpkin list of birds list of extinct birds list of fossil birds lists of birds by region loon lybiidae maluridae megalaimidae melanocharitidae modern birds molecular biology mousebird neognathae neomorphidae nightjar ornithology orthonychidae ostrich owl paleognathae pardalotidae parrot passerae passerine pelecaniformes pelican penguin petroicidae phasianidae pheasant piciformes plumage procellariidae procellariiformes puffbird rallidae ratite roller sandgrouse scolopacidae seabird sittidae stork sulidae sungrebe swift taxonomic rank taxonomy tern the clements checklist of birds of the world threskiornithidae tinamou trogon tropicbird tubenose turaco tytonidae uropygial gland wader woodpecker